Found the culprit: It's any of the e10s-shims enabled in Nightly 2014-11-03, see https://bugzilla.mozilla.org/show_bug.cgi?id=1063156
Last good revision: 0e631971b841 (2014-11-02)
First bad revision: 0b81c10a9074 (2014-11-03)
Pushlog: https://hg.mozilla.org/mozilla-central/ ... 81c10a9074
Opening the filter preferences, with sorting set to "Last hit":
Before that build takes about 1 second,
With that build and all newer builds it takes 3 seconds.
Opening the filter-options of EasyList ("Actions"), with sorting set to "Last hit":
Before that build it takes about 3 to 4 seconds.
With that build and all newer builds it takes more than 10 seconds.
You can disable the shims in recent Nightlies with extensions.interposition.enabled;false
With that config set, the times drop back to the level of before 2014-11-03.
The regression-range above applies to non-e10s. NOTE: Even with e10s disabled, the user is affected by the e10s-shims!
With e10s enabled, the range is:
Last good revision: 095d2a9c2be5 (2014-07-15)
First bad revision: 869971ad9fd6 (2014-07-16)
Pushlog: https://hg.mozilla.org/mozilla-central/ ... 9971ad9fd6
"Initial compatibility shims for e10s"